Electric welding



May 12 1942 l.1. HgMURcH v2,282,339 A ELECTRIC'WELDING Filed April 2o,1940 A 255A Z2! A A' A 2,/ z5 E .55 (Z5 fi 7 l/ A 33 30 Patented May 12,1942 ntac'rarc waLnnvG John H. March, East Orange. N. J., assignor toAmerican Can Company, New York, N. Y., a corporation of New JerseyApplication April 20, 1940, Serial No. 330,762

8 Claims.

The present invention relates in general to spot welding machines andhas particular reference to the simultaneous spot welding of the sideseams of two can bodies and to a two step welding treatment whichproduces can bodies as an incident to further can forming operations,the invention being particularly adapted for welding treatment ofrelatively short height can bodies. In some respects the presentinvention is an improvement of the J. A. Toleik Patent 1,773,892,

issued by the United States Patent Oflce on August 26, 1930, andrelating to Electric welding. An object of the invention is theprovision of y a spot welding unit for incorporation in a can prisingdouble sets of electrodes located rela-vl tively close together andadapting the machine for the simultaneous spot welding of the frontseamend of a short height body and the rear seam e l of the nextadjacent body in the'rear of the procession, the rear body after havingits rear seam edgetack welded being moved to the position occupied bythe former front body for` the second operation, at which time it willhave the front edge of its side seam tack or spot weld- In the presentembodiment Aof the fnvention/ similar combination lock and lap seamsformed in the can body undergoing treatment may be used. When can bodiesof very short height are used, in some instances the entire seam islapped and there are no locked sections. In such cases it is necessarymerely to provide outside guide rails and sizing wings in addition tothe regular body maker parts illustrated.

The spot welding of the can body seams is in no wayconcerned withwhether the seam is fully lapped, fully locked or is a combination oflock and lap sections. The necessary guide rails and sizing side wingsrequired where the seam is fully lapped are well known parts of theconventional can body making machine and it is believed furtherreference to this feature is unnecessary. It will be understood,therefore, that the welding unit illustrated in the drawing by way ofexample is adaptable for spot welding can bodies having any of theaforementioned types of seam.

In the drawing there is disclosed a mandrel or horn 2l which may be apart of a conventional body making machine. ACan bodies A may be formedon the horn 2| in any suitable manner and as received in a weldingstation B of the present apparatus are ready for welding without furthertreatment.

In reaching the welding station B the can bodies A are advanced by afeed bar 22 which has ed simultaneously with the spot welding of thestood from the following description,l which, taken in connection withthe accompanying drawing, discloses a preferred embodiment thereof.

The single view in the drawing shows an elevation of the principal partsof the welding unit embodying -the present invention such a unit beingapplied to a can body making horn with parts l shown in section.

.In the Toleik patent referred to above can bodies having inner hookedblank edges with lapped sections which constitute the body side slidingmovement in a groove 23 formed in the top of the horn 2l. Such a feedbar 22 carries the usual spring pressed feed dogs 24, these dogs beingpivoted on pins 25 and being arranged to normally extend above the feedbar 22 and in engagement with the rear edge 0f the can body A.

Such a feed bar. is reciprocated in any suitable manner and on thefeijward stroke advances the can bodies A along thehorn in processionalorder. On the return stroke of the feed bar, the feed dogs 24 swing backbelow the top edge of the bar pivoting on the pins 25. In this pomtionblank for the next forward stroke. In this manseam, after being tack orspot welded to hola the parts closely together, may be subsequentlysoldered or otherwise more completely joined,

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ing. i. e., at the rest period of thecanbodyad vancernent. Each body ispresent in the welding station for two welding operations. In the firstto the sides of the respective electrodes 3|.

of these operations the body occupies the rear of two positions in thestation. At such time its 30, this recess extending throughout thelength of the welding station B and back toward the rear end of the horn2| for a. further distance. A pair of welding disc electrodes 3| aremounted side by side on the inside of the horn and within the recess 30,each electrode being rotatably mounted on a pin 32 which is anchored ina central web part 33 of the horn 2| The outer p eriphery of eachelectrode 3| extends at the bottom tothe peripheral bottom surface ofthe hornt 2| and the two can bodies at the weldingstation B. during thewelding operation rest in tangential contact with these electrodes.

" I'he can body occupying the rear position at station B is indicated asA' and the can bodyv in the forward position as A'. The electrodes 3 arein such position4 that the rear can body A' contacts the rear electrode3| at the back edge of its side seam. In a similar manner the front canbody A2 has tangential contact with the forward electrode adjacent theforward edge of its side seam. l

At the bottom ofthe horn an insulating member 34 is inserted in therecess 33 in order to partially close offthe recess at the bottom. Suchinsulating member is cut out to clear the two electrodes 3| so that eachelectrode may properly engage its associated can body A' or A:l whenthese bodies are at the welding station.

feed dog pivot pins 25, thisparticular pin being marked`53 todistinguish it` from the others, is projected laterally from the feedbar 22. When the bar is moved back `on its rear or return Provision ismadeV for changing the position of l horn recess. Shoulder screws 35extend through slots 31 cut through the slide 35.

A pawl member 33 is pivoted at 33 on the forward end of the slide 35 andextends forward into a position over the two electrodes 3|. The pawl 33is formed with a front tooth 4| and an intermediate tooth 42 and theseteeth overlie and engage the teeth of ratchets 43, 44 secured The pawlteeth are pressed into operative connection with the teeth of theratchets 43, 44 by a leaf spring 45. Such a spring is pinned to -theslide 35 and projects forwardly over and engages the stroke, the pin 53strikes the arm 5| and shifts the slide 35 back, this being just as thefeed bar comes to the end of its backward stroke.

` The slots 31 permit this movement of the slide 35 and the teeth 4|, 42of the pawl 35 which are then in engagement with the teeth of theratchets 43, 44, turn the electrodes counter-clockwise, as viewed in thedrawing. This movement of the slide takes place against the tension of'the spring 41 and as a result thereof a. new welding surface of theelectrodes 3| is presented.

Upon the following forward travel of the feed bar 22 the pin 53 leavesthe arm 5| and the spring 41 thereupon pulls thev slide 35 and its pawlforward until the arm strikes the forward edge of the slot 52, thisbeing the position shown in the drawing.' In arriving at thispositionthe spring 45 yields\suiliciently to permit the pawl 38 to pivoton its pin `32| so that the pawl teeth 4|, 42 pass over and engage intoadjacent teeth of the respective ratchets 43, 44.

Outer electrodes-5| are adapted to cooperate with the electrodes 3| inperforming the welding operation. The electrodes 5| are shownas circulardiscs which are rotatably mounted upon pins 52. These pins are anchoredin a cross head 53 which is disposed below the horn 2| at the weldingstation' B. 'I'he `two electrodes 5| are adapted to be brought intoengagement with the two can bodies A', Az located at the weldingstation. Following each welding operation electrodes 5|, like the innerelectrodes, are rotated on their mountings 52 tochange the weldingsurfaces for each subsequent welding operation.

For this purpose each electrodel 5| is fixed to and carries a ratchet 54and each electrode and- `into contact with its associated can body forcooperation with its`corresponding electrode 3|,

the cross head 53 is adapted to be raised and lowered in synchronismwith the operation of the feed bar 22. This movement of the cross head53 is timed so that the electrodes 5I are brought into welding positionimmediately after the can bodies A' and Az at the welding station B cometo rest in their intermittent advancement along An arm 5| formed ,on theslide 35 extends up through a slot 52 cutfin the top of the horn, thearm where it is above the wall of the horn ex tending alongside of thefeed bar .22. One 'of the the body maker horn 2|.

A slide block or support 15 is disposed below the horn 2| an`d ispreferably an integral part of the machine frame. Such a support 15constitutes a guide lmember forv movable parts associated with thewelding operation. For this purpose guide member 15 is provided with twoguideways 13, 11 in which are mounted reciprocating slides 13. '13. Theslide parts'13, 13 are preferably provided -'with tongue sections 3l,-32 which fit within corresponding groove parts in lthe guideways 15, 11.Slide gibs 33, 34 are also provided for more even holding action of theslide members 3|. 32 and these may be adjusted by adjusting screwsthreadedly secured in the support member 15.

The slide 13 carries the crosshead 53 and l tact member or blockissmbunted in the rear part of the recess 00 of the horn. Such a memberis anchored to the web 33 by bolts |02. The

insulation 24 which closes oi! the bottom of the horn recess is slottedat |03 and this permits a movable contact member |0410 pass up into thehorn and into electrical engagement with the block. Contact is made whenthe slide 10 is raised.

The movable contact member |04 Ais carried in a contact head |05 whichis mounted on the upper end of a slide rod |06 which extends down into aslide block section |01 carried by the slide 19. The lower end of therod |06 is enlarged at.|08 andis hollowed out to partially enclose aspring |00 which is held in the hollow end of the rod by a screw plugthreadedly secured to the block |01. This provides a yieldable mountingfor the movable contact member |04v and permits engagement of thecontact andthis, operating through the system of links. imi'iltaneouslylowers the two slide members This lowering action removes .the outerelectrode 0| from contact with the work and at the same time allows forthe bar 00 associated with each outer electrode to operate against itscorresponding ratchetll to rotate the associated electrode 0| so that anew surface will be pre- Y sented for the next welding operation.

'Thetimingofthemachineissuchastore-- peatedly weld. two can bodies eachtime such bodies are positioned at the station B.v Each weldingoperation therefore follows as a result of raising the cross head I3with its electrodes 6| and by completing theelectrical circuit at thecontact members |04 and |0|. The slide block |01 is preferably insulatedfrom the slide 12 by lbeing formed of electrical insulating material.

In a similar manner the block section III of the .slide 1B may also beformed of insulating materiaL It .is believed that detailed explanationof the wiring circuits is unnecessary in view of the similarity of thepresent construction with usual welding circuits as in `the aforesaidToleik patmember with the stationary horn contact block |0| and allowsfor a further raising of the slide 19 without detaching these parts. Thehead |05 also carries a depending pilot pin ||2 which has slidingmovement in a bore ||3 formed in the block |01. This prevents turning ofthe rod |06 within the block.

The cross head 03 is mounted in a similar manner upon a rod ||5 whichcorresponds in construction to the rod |00 of the contact member |04.Such a rod Il! is yieldably mounted in a block section IIB `of the slide10. This insuresa proper engagement of the electrodes 6| against theseam of the can bodies being welded and permits excessive liftingmovement of the slide 10 without disturbing the contac of the electrodeswith the work.

The two slides 18, 19 ,are adapted to be lifted in unison and this isaccomplished by .operation of a toggle system connected with the lowerends of the slides. A pair of links ||0 are used for the slide 18, theupper end of one of the links being pivoted at ||0 to the slide 12. Thelower end of the opposite link ||0 is pivoted at |2| to a dependingplate section 22 of the sup# port member 15. The two links ||l arepivotally connected at |22. This pivot connection |23 also provides forpivotal engagement with a connecting nnk m which is yassociated with atthe common pivot |21. The arm |l| is the same length between pivotalcenters |21; |20 as thelinks III and |2l. l

This therefore provides a system of parallel link coordination so thatwhen the lever |20 is moved in a counter-clockwise direction or to theright as illustrated, the slides 1l, 10 are simultaneously raised intothe operating or welding position illustrated in the drawing. After thewelding operation has been completed the lever ent. One side of asuitable electrical circuit may be made by contact directly with acontact member |31 formed in the block |05 by meansA can bodies betweenthe electrodes thus make two spot welds on each side seam.

It is thought that the invention and many of its attendant advantageswill be understood from the foregoing description, and it will beapparent that various changes may be made in the form, construction andarrangement of the parts without departingfrom the spirit and scope ofthe invention or sacriiicing all of its material'advantage's, the formhereinbefore described beingl .merely a preferred embodiment thereof'.

1. In a machine for simultaneously welding. separate can bodies and thelike. the combination of a horn for supporting a plurality of can bodiesto' be welded, each of said bodies having contacting areas constitutingbody sideseams. means for movlngsaid cam bodies' in a continuousprocession along said horn with their side seams following apredetermined path of travel. a welding device comprising a double pairof electrodes arranged inside and outside of said horn respectively andin the path of travel of the saidy side seams. and means for producingrelative motion between the inner and the outer of said electrodes for awelding operation to simultaneously tack weld spaced seam areas ofseparate can bodies.

2. In a machine for simultaneously welding separate can bodies and thelike, the combinal tion of a horn for supporting a plurality of canbodies to be welded, each of said bodies having contacting areasconstituting body side seams, means for moving said can bodies in acontinu- |2315 moved in the reverse or clockwise direction ousprocession along said horn with their side seams at the bottom of thehorn, a pair `of inner electrodes located inside of said horn andadapted to simultaneously engage inside of the side seams of twoseparate can bodies, a pair of outer electrodes located beneath saidhorn and adapted to simultaneously engage below and against the saidside seams of said separate can bodies and to cooperate with said innerelectrodes to perform a welding operation on said body seams, and meansfor moving said outer electrodes into weld- Aing position on said seamsto simultaneously tack weld parts of both seams of said separate canbodies.

3. In a machine for simultaneously welding the side seams of separatecan bodies and the like..

the combination of a horn for supporting a plurality of can bodies to bewelded, each of said bodies having contacting areas constituting bodyside seams, feeding devices for advancing said can bodies in spacedrelation along said horn with their side seams following a common pathsaid outer electrodes respectively against the side.

of travel, inner welding electrodes arranged inside of said horn in thepath of travel of said seams and in position to be engaged by the sideseam area of two adjacent and separate -can bodies when the latter arefed into welding position, outer welding electrodes arranged outside ofsaid hom and adapted to be moved into the combination of a horn forsupporting a plurality of can bodies to be welded, each of said bodieshaving contacting areas constituting body side seams, feeding devicesfor advancing said can bodies in spaced relation along said horn withtravel, a plurality'` of spaced inner rotativewelding disc electrodesarranged inside of said horn in the path of travel of said seams and inposiadjacentand separate can bodies when the latter are fed into weldingposition, a plurality of spaced'outer rotatable welding disc electrodesarranged outside of said horn and adapted to be moved into the path oftravel of said body side l seams, means for simultaneously clamping theside seams of said adjacent can .bodies which are in said weldingposition between said inner and outer disc electrodes to effect awelding operation simultaneously onl the two separate can bodies.'

and means for rotating said electrodes between welding operations.

5. In a machine for simultaneously welding the side seams oi' separatecan bodies and the like,

the combination oi' a horn for supporting a plu-l rality of can bodiesto be welded, each of said bodies having contacting areas constitutingbody side seams, feeding devices for advancing said can bodies in spacedrelation along said horn with their side seams following a common path'of travel and for simultaneously bringing two adjacent and separate canbodies into welding position, a pair ot spaced inner welding electrodediscs rotatably mounted in said horn with one disc above and in contactwith each separately positioned can body seama slide member mountedbelowsaid horn, a pair of outer welding electrode discs rotatably mounted onsaid slide mem-` .45 tion to be engaged by the side seam area of twotheir side seams following a common path of c seams'of said separate canbodies while in welding position and to clamp each engaged side seamsection against its respective engaged inner electrode to eilect awelding operation simultaneously on the two independent can bodies.

6. In a machine for simultaneously welding the side seams of separatecan bodies andthe like, the combination of a horn for supporting aplurality of can bodies for welding, said horn constituting, a part of awelding circuit, each of said bodies having contacting areasconstituting body side seams, feeding ldevices for advancing can bodiesin spaced relation along said horn with their side seams following acommon' path of travel and for simultaneously bringing two adjacent andseparate can bodies into welding position, a pair of spaced innerwelding electrode discs rotatably mounted in said lhorn with said discsabove and disposed respectively in contact with ,the side seams of saidpositioned separate can bodies, a slide member mounted below said hornand constituting a part of the welding cir- I cuit, a pair of outerwelding electrode discs rotatably mounted on said slide member andspaced seams of the two spaced and positioned separate can bodies.r

7. In a machine for simultaneously welding the side seams of separatecan bodies and the like,

.the combination of a horn for supporting a plurality of can bodies tobe welded, each of said bodies having contacting areas which constitutebody side seams, a pair of inner spaced electrodes located in said hornat a welding station, feeding devices for intermittently advancingV canbodies along said horn, said feeding actionk terminating to place twoseparate and adjacent `can bodies in said welding station with theirside seams respectively in contact with said spaced inner electrodes, apair of outer electrodes located at said welding station disposedoutside of said horn each in alignment with a said inner electrode, andmeans for simultaneously moving said outer electrodes respectivelyagainst the two separate can body side seams to hold such seam partsrespectively between an inner and an outer electrode for a simultaneousation on both can bodies.

8. In a machine for simultaneously welding the side seams of separatecan bodies and the like, the combination of a horn for supporting aplurality of can bodies to be welded, each of said bodies havingcontacting areas which constitute body side seams, -a pair of innerlongitudinally spaced electrodes located in said horn at a weldingstation, a forward electrode engaging the side seam of the iirst andforwardly disposed of a pair `of separate and spaced can bodies at saidwelding station while the other electrode engages the side seam of therearmost of said bodies, a pair of outer electrodes located at saidwelding station and disposed outside of said horn respectively inalignment with said inner electrodes, means for moving said outerelectrodes simultaneously and ber,l and means for raising said slide tobrins r respectively against the two can 'body side seams welding opertohold such seam parts of said separate can bodies respectively between aninner and an outer electrode for a welding operation wherein the forwardcan body seam is welded at its front edge 1 only and the rear can bodyseam is simultaneously welded at its rear edge-only, and feeding devicesfor simultaneously moving said forward can body out o! said weldingstation and said `rear can body into the forward position therein whileat the same time advancing a. succeeding can body into the rear positiono! said welding station for a succeeding welding operation, whereby theilrst can body occupying the forward position at said station will haveits side seam welded at both its front and rear edges and saidsucceeding can body is welded at its rear edge only.

JOHN H. MURCH.

